Water tube boiler



DeC- 14, 1937. A. o. BLATCHFORD v 2,101,892

'WATER TUBE BOILER Y Filed June l, 1937 UNlTED STATES PATENT orricsWATER TUBE BOILER Albert Oliver Blatchford, Amballes, Guernsey,

Channel Islands l Application June 1, 1937, Serial No. 145,821

In Great Britain 2 Claims.

The chief object of the present invention is to provide a water tubeboiler for the production of steam or hot Water, or a water heater forhothouse and domestic plant in which the maximum efliciency is obtained.In Water tube boilers in which the products of combustion are free topass up between the parallel tubes a great deal of -eciency is lostowing to all or some of the products of combustion merely passingbetween laterally spaced tubes somewhat freely to the stack. And also ifsome of the conduits appropriate to the complete circuit of the tubesare outside the boiler shell, loss in efficiency arises due to radiationwith the externally disposed parts whilst sluggishness in circulationoccurs due to parts being directly exposed to cooling air. Anotherobject -oi this invention is toprovide a water tube boiler in which theproducts of combustion are forced to traverse a Zig-zag ascending pathalong the tubes without the loss in efflciency arising out of parts ofthe tubes or conduits connecting the successive banks of tubes beingoutside the boiler shell or isolated from the influence of the ascendingproducts of combustion.

In order that my invention may be clearly understood and readily carriedinto effect I have appended hereto a sheet of drawing, somewhatdiagrammatic, illustrating embodiments thereof, and wherein:-

Fig. l is a sectional side elevation of a boiler,V

and

Fig. 2 is a detail sectional View showing a modied arrangement of bailleplate.

Referring to the drawing the furnace is indicated by the referencenumeral l and is disposed in the base of an outer shell (2) providedwith a suitable furnace charging door or doors (3) and any suitableinspection cover or covers. The 4.0 water tubes (4) are arranged inbunches, four bunches, a, b, c, and d being shown merely by way ofexample, as any convenient number may be adopted. Each bunch of tubesconsists of any suitable number of tubes arranged side by side fornearly the full transverse inner dimension of the shell (2), and also,although I have only shown one line of tubes for each bunch, a number oflines can be arranged close together, the tubes of successive linespreferably being staggered.

The ends of the tubes are engaged in headers 5, these headers beingarranged in pairs joined by short ascending pipes 5, with of course theexception of the uppermost and lowermost headers which need only besingle members. The

September 29, 1936 uppermost header is connected by a pipe 'l to thesteam space of a drum 8, the latter conveniently being arrangedvertically alongside the shell 2. The base of the drum is connected tothe lowermost header by a pipe lil. The headers are located close to thefront and rear walls of the shell 2 to avoid as much as possible largeareas of idle space, and the shell 2 is preferably formed withtransverse channels or pockets il opposite the headers to assist inguiding the products of combustion on the ascending circuitous path overthe layer of each pair of headers and through the narrow horizontalspace between each pair of headers as indicated by the arrows.

rIihe tubes are arranged at a very shallow angle of inclination so thatthey ascend in Zig-zag manner, and the products oi combustion followsuch. a path, this result being assisted by baliles l2 of heat resistingmaterial preferably laid upon the tubes 4 and having suilicientclearance at their ends to expand. After the products of combustion havetraversed the tubes a, b and c such products escape through the spacesbetween the tubes of the upper set d into the flue I3.

If desired, a number of sets of tubes, arranged in the herebeforedescribed manner, can be arranged alongside each other, on oppositesides of the said drum so that there are more than one lowermost headerto be connected to the drum. Although I have described a vertical steamand Water drum it is of course understood that a horizontal drum can beadopted, the important feature of this invention being the arrangementof tubes and headers.

If desired the baliles l2 may each take the form of a pair of ironsheets l2a and i211 as shown in Fig. 2 Which rest loosely upon the tubesand overlap so as toprovide for expansion and contraction.

What I claim iszl. In a Water tube boiler or water heater, a pluralityof sets of tubes arranged in a zig-zag manner, headers arrangedtransversely to the tubes and receiving the ends or the tubes,` saidsealed in relation to the shell against free passage of products ofcombustion past it vertically.

2. In a water tube boiler or water heater, a plurality of sets of tubesarranged in a zig-zag manner, headers arranged transversely to the tubesand receiving the ends of the tubes, said headers being arranged innarrowly spaced pairs,

` short ascending conduits connecting each pair of headers, balescovering the upper sides of the 10 tubes for their full length, an outershell totally

